I am designing a stop system for a old diesel engine. The application I am using needs a pull type solenoid that can have a stroke of 9/16" - 1 1/2". it needs to have a return spring of at least 20 lbs. It needs to be continuous duty ( probably 2 coil).This will be used as a "engage to run" setup. The spring loaded solenoid will push the injector shut when power is removed.

I have looked at several brands including F. W. Murphy and Trombetta. These do not seem to meet my requirements. I did however find some in the woodward/synchrostart line that will work, however they are quite expensive. Can anyone tell me what some other companies are that make diesel stop solenoids?

Those things aren't cheap. Also, if you operate them on an incorrect voltage, or the plunger doesn't retract all the way, you can burn them up very quickly - a couple of minutes, tops.

We had to replace one for a retired USMC 5-ton truck last year. Cost $150 from Caterpillar. It's a 28v version. By the way, you didn't specify the voltage of your system; since it's an "old diesel engine" the voltage could be anything.

If you're looking to do this "on the cheap", then you might try going to a salvage yard where they part out diesel trucks. At least you may find out more information from people who are actually in that business.